David Saltzberg, 25 Nov. 02 ANITA meeting Slide 1 Calibration Talking Points l Pulser äChecking payload channels under construction äTiming in all channels äCoarse idea of antenna beam patterns äPulsing system during flight l On-board gain calibrators äWhat relation of system temperature to V rms for each channel l Online monitoring

David Saltzberg, 25 Nov. 02 ANITA meeting Slide 2 Pulse types l Method 1: Fast, broadband pulse äCan get Avtech pulse ~ 200 V pk2pk into 50  W instantaneous ä(eg 40 psec risetime  0.1 to 6 GHz bandwidth) äGood for timing in system (sub- nanosecond) ä Power shared among bands l Method 2: äNarrow band pulse with reasonable timing: 2-10 nsec äCan amplify easily to 25 W - (up to 500 MHz, can get to ~1000 MHz?) äGives more power in band äNot for checking triggering Volts 1 nsec 40 ps r.t.

David Saltzberg, 25 Nov. 02 ANITA meeting Slide 3 Transmitting ground to balloon l Could reasonably transmit 25 W into 1000 MHz band l Assuming 80km line of sight  -80 dBm in 300 MHz äthermal noise in 300 MHz bandwidth is -90 dBm äSo should be visible l “Standard gain horn” can transmit broadband pulse with good phase center with 15 dBi directivity. Will be large for 200 MHz. But could test triggering l Narrow band pulses can be more easily transmitted and detected. l How many ground locations?

David Saltzberg, 25 Nov. 02 ANITA meeting Slide 4 On board “mini-cal” l To determine system temperature of each channel….from physics point of view, says how well we know our threshold äHarsh environment could alter our gain & noise levels relative to ground äSets absolute scale of V rms äPrefer switch in load and/or noise diode in front of LNA - Need to do this without reducing sensitivity of nominal system - If we trust gain & noise of LNA, do this downstream of LNA? äAdds complexity. äCould instrument this on a few channels and carry it to others based on V rms from ice in aperture.

David Saltzberg, 25 Nov. 02 ANITA meeting Slide 5 Other in-flight calibrators l Sun: Could map out antenna beam ä(0.5 deg vs. ~60 deg) äIntensity varies on mostly long timescales äShould be bright enough to see l Moon: äSimilar size to Sun äAbout 200 K, but does not fill beam. äWell known temperature äEven using averaging SNR is very small ~10 -4 l Anyway get this for free with some number of random (“zero bias”) triggers (~0.1 Hz)

David Saltzberg, 25 Nov. 02 ANITA meeting Slide 6 Online Monitoring l Should be monitoring data from ground äTaking “zero-bias” or “minimum bias” data äV rms (T sys ) on each channel äFrequency power spectrum for each channel ~1MHz res’n äTrigger rates - Singles rates per channel - Intermediate coincidence rates - Trigger rates ä~ 5-10 minute time response